ALTITUDE SICKNESS INFORMATION
Altitude Sickness
Different people under similar conditions will respond quite differently to
altitude. There are no specific factors such as age, sex, or physical condition
that correlate with susceptibility to altitude sickness. Your response to
altitude will depend on your rate of ascent, the magnitude of the ascent, and
your individual susceptibility (genetics). The effects can be mild or severe,
and are caused by a lack of oxygen to the muscles and brain. As altitude
increases the concentration of oxygen stays the same, but the number of oxygen
molecules per breath is reduced as the barometric pressure drops. At 5,500 m
(18,000 ft), there is half as much oxygen available as at sea level. In some
cases altitude sickness can turn extremely severe, even fatal. For reasons not
entirely understood high altitude and lower air pressures can cause fluid to
leak from the capillaries and build-up in the brain and lungs. Continuing an
ascent without proper acclimation can lead to a life threatening illness.
Acute
Mountain Sickness (AMS)
Mild
symptoms of acute mountain sickness will occur in 75% of people who travel over
10,000 feet, and can affect some people at lower altitudes.
These
symptoms include:
Fatigue
Dizziness
Headaches
Nausea
Disturbed sleep
Indigestion
Loss of Appetite
Vomiting
These
symptoms typically begin immediately after arrival and tend to worsen at night.
Mild AMS does not interfere with normal activity and symptoms generally
subside within 2-4 days as the body acclimatizes. As long as symptoms are mild
and only a nuisance, ascent can continue at a moderate rate.
Prevention of AMS
Altitude
sickness is preventable! Pay close attention to your body and the health of
individuals in your group. Immediately communicate any symptoms of illness to
others on your trip, since oxygen deprivation of the brain may cause individuals
to deny or not recognize their own symptoms.
STAY
HYDRATED urine output should be copious and clear. Try to drink at least
4-6 litres per day.
AVOID tobacco, alcohol, and other depressant drugs including barbiturates,
tranquilizers, and sleeping pills. They further decrease the respiratory drive
during sleep resulting in a worsening of symptoms. In addition, avoid diuretics
such as coffee and tea.
DONT GO UP UNTIL SYMPTOMS GO DOWN people acclimatize at different
rates, so make sure that your entire party is properly acclimatized before going
higher. Rest at the same altitude is efficient for mild symptoms, but if they do
not go away within a day or two it is essential that you descend immediately.
DIAMOX (acetazolamide) is a drug shown to be effective in minimizing the
symptoms caused by poor oxygenation by helping you breathe deeper and faster.
This drug is not used in treatment, it should be used as a preventative measure
only. The recommended dose is 125 mg twice a day, and it is advisable to start
taking it 24 hours before you go to altitude and continue for at least five days
at higher altitude. Side effects include tingling of the lips and finger tips,
blurring of vision, and alteration of taste. If you are allergic to sulfa drugs
you should not take Diamox. Use of this drug is controversial, so it is
advisable to research its effects prior to seeking a prescription. Here are a
couple of sites for your convenience:
http://www.healthsquare.com/newrx/dia1131.htm
http://www.basecampmd.com/expguide/diamox.shtml
EAT high-carbohydrate foods while avoiding fatty foods.
BEFORE your trip, maintain a good work/rest cycle, avoid excessive work
hours, and last minute packing.
LISTEN to your body. Do not over-do things the first day or two. Avoid
heavy exercise.
High
Altitude Pulmonary Edema (HAPE)
HAPE results from fluid build up in the lungs, which prevents effective
oxygen exchange from the lungs to the bloodstream. This is a very serious
condition that can lead to death if not treated immediately.
Symptoms
of HAPE include:
Irritating cough (can produce frothy, often blood-tinged sputum)
Mental confusion, staggering drunken walk
Quick shallow breathing, difficulty breathing
Exhaustion
Chest pain
Gurgling noise in chest
Debilitating headache and severe fatigue
Disruption of vision, bladder, and bowel functions
Loss of coordination of trunk muscles (test by walking straight line)
Although
rare, HAPE frequently strikes young fit climbers and trekkers. If you
notice any of these signs in yourself or others in your group you must descend
immediately, even at night. HAPE can be fatal within a few hours if left
untreated. However, if diagnosed early, recovery is rapid with a descent of only
500-1,000 meters. Besides descent, treatment also includes rest, administration
of oxygen, and portable hyperbaric chambers.
High
Altitude Cerebral Edema (HACE)
HACE
occurs when fluid leakage in the brain causes swelling which affects the central
nervous system. This is considered the most serious altitude related illness. If
left untreated it will lead to coma and death. HACE is thought to occur in 1% of
persons above 4,000 m and 3% of those with AMS, and usually occurs after a week
or two at high altitudes.
Symptoms of HACE can be similar to AMS and HACE and include:
Drowsiness
Headache
Changes in Behavior
Staggered gait (unable to walk heel-to-toe in a straight line)
Severe weakness/fatigue
Impaired mental processing, confusion
Difficulty Speaking
Blindness
Vomiting
Paralysis of a Limb
Decreasing levels of consciousness (loss of memory, hallucinations, psychotic
behaviour, and coma)
Seizures
Immediate descent is the best treatment for HACE. This is of the utmost
urgency, and cannot wait until morning. The moment HACE is recognized is
the moment to start organizing an effort to get this person down the mountain,
usually to the point where they last slept with no symptoms. It is important to
recognize that persons with this illness are often confused, and may not
recognize that they are ill.
Note: The information provided here is
designed for educational use only and is not a substitute for specific training
or experience.
